It is the people who rely on the commentaries, like [REMOVED BY A MODERATOR], who talk a lot about ''doer''
They say that being enlightened is when there is no doer, instead there is ''pure action'' or ''pure phenomena''.
for instance Mahasi quotes this
Thus one realizes that feeling itself is what feels the plea- sure
associated with pleasant sense objects and so on. We con- ventionally
say with regard to the appearance of feeling, “I feel.” 512 In order
to point out that there is no doer apart from actual phe- nomena, the
commentary says that feeling itself is what feels. 513
https://wisdomexperience.org/academy/wp-content/uploads/sites/4/2016/07/Manual-of-Insight-for-Course.pdf
The pali word they use is ''Karaka atta'' http://www.abhidhamma.com/Mahasi_anatta.pdf
you have to read all their texts to know what they say about ''a doer''.
Their obsession with the doer comes from their lack of understanding the baya sutta, where they cram their view of lack of doer, instead of lack of craving, because the popular view is that ''people suffer because they judge, so when they do not judge they do not suffer'', and ''phenomenologically'' it would mean that there is no subject-object, ie no doer, but only phenomena .
If you want a sutta talking about doer (or lack of doer) there is this
https://www.accesstoinsight.org/tipitaka/an/an06/an06.038.niza.html
“I have not, brahman, seen or heard such a doctrine, such a view. How,
indeed, could one — moving forward by himself, moving back by himself
[2] — say: ‘There is no self-doer, there is no other-doer’? What do
you think, brahmin, is there an element or principle of initiating or
beginning an action?”[3]
“Just so, Venerable Sir.”
“When there is an element of initiating, are initiating beings [4]
clearly discerned?”
“Just so, Venerable Sir.”
“So, brahmin, when there is the element of initiating, initiating
beings are clearly discerned; of such beings, this is the self-doer,
this, the other-doer. [5]
“What do you think, brahmin, is there an element of exertion [6] ...
is there an element of effort [7] ... is there an element of
steadfastness [8] ... is there an element of persistence [9] ... is
there an element of endeavoring?” [10]
“Just so, Venerable Sir.”
“When there is an element of endeavoring, are endeavoring beings
clearly discerned?”
“Just so, Venerable Sir.”
“So, brahmin, when there is the element of endeavoring, endeavoring
beings are clearly discerned; of such beings, this is the self-doer,
this, the other-doer. I have not, brahmin, seen or heard such a
doctrine, such a view as yours. How, indeed, could one — moving
forward by himself, moving back by himself — say ‘There is no
self-doer, there is no other-doer’?”
Bikkhu sujato translate attakāro as ''one's volition''